--- license: permission_granted topic_id: companion_breed_health_shih_tzu_dew_claws_canine_preaxial_polydactyly_dog category: companion-breed-health title: "Shih Tzu — Dew claws, canine preaxial polydactyly (hereditary; OMIA-verified breed predisposition)" lang: en source: "OMIA (Online Mendelian Inheritance in Animals, University of Sydney) breed-specific hereditary-disorder record, saved verbatim to source_file; C1 substring-verified. Pulled 2026-08-02 from local OMIA database dump." source_file: pdf-raw/breed-health/shih_tzu_dew_claws_canine_preaxial_polydactyly_1462.txt date_parsed: 2026-08-02 tokens_estimated: 230 verification: method: substring_match claims: 5 passed: 5 date: 2026-08-02 recovered: false path: companion-breed-health/companion_breed_health_shih_tzu_dew_claws_canine_preaxial_polydactyly_dog/01_companion_breed_health_shih_tzu_dew_claws_canine_preaxial_polydactyly_dog.md source_document: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" citation: authority: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" title: "Shih Tzu — Dew claws, canine preaxial polydactyly (hereditary; OMIA-verified breed predisposition)" url: "https://omia.org/OMIA000810/9615/" retrieved: "2026-08-02" ref: "OMIA breed-specific hereditary-disorder records (omia.org), derived from local OMIA database dump; dataset: https://doi.org/10.25910/2AMR-PV70" doc_type: "academic animal-genetics database (breed-specific disorder entries)" needs_review: false
Shih Tzu — Dew claws, canine preaxial polydactyly (hereditary; OMIA-verified breed predisposition)
Source: first-hand OMIA (University of Sydney) breed-specific hereditary-disorder record, saved verbatim to source_file; every claim below is a C1 byte-substring of it.
Claims
Breed: Shih Tzu (Dog)Disorder: Dew claws, canine preaxial polydactylyMode of inheritance: Autosomal dominantClin feat: Park et al. (2008): “Canine preaxial polydactyly (PPD) in the hind limb is a developmental trait that restores the first digit lost during canine evolution. … As described previously (Park et al. 2004), the restored phenotype is slightly overmanifested, generating one or more preaxial digits. As a matter of fact, the external morphology of hind-limb-specific canine PPD is slightly different from other polydactylies in that only the claw is observed as having an extra digit with fibrous tissue connecting the region between the tarsal and the first metatarsal bones, which either is reduced in size or is incomplete with a lesser deposit of bony material (Miller 1979; Park et al. 2004).”Defect: yes
Associated gene(s)
Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.
- Gene: Entrez Gene ID 388304145 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene
- Gene: Entrez Gene ID 388304937 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene
- OMIA molecular-genetics note: Park et al. (2008) identified within the two identified distinct affected haplotypes for Asian and Western breeds two different single-base changes in the upstream sequence (pZRS) of the ZRS. A G to A variant named DC-1 was found in the 1-kb region upstream of the 5′-end of the ZRS in 150 affected Sapsaree (144 affected dogs were heterozygous G/A and 6 affected dogs homozygous A/A) and six affecte…
Evidence (references)
Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.
- 1941. On the mode of inheritance of dew claws in the domestic dog. Nuova Veterinaria — OMIA Phene_Article / Article
- 1954. The inheritance of polydactyly in the domestic dog — OMIA Phene_Article / Article
- 1985. Developmental constraints: why St. Bernards often have an extra digit and poodles never do. American Naturalist — OMIA Phene_Article / Article
- 2008. Canine polydactyl mutations with heterogeneous origin in the conserved intronic sequence of LMBR1. Genetics — PubMed:PMID18689889 | DOI:10.1534/genetics.108.087114 — OMIA Phene_Article / Article
- 2015. Molecular Genetics of Sex Identification, Breed Ancestry and Polydactyly in the Norwegian Lundehund Breed. J Hered — PubMed:PMID25994807 | DOI:10.1093/jhered/esv031 — OMIA Phene_Article / Article
- 2004. Linkage of the locus for canine dewclaw to chromosome 16. Genomics — PubMed:PMID14706450 | DOI:10.1016/s0888-7543(03)00234-9 — OMIA Phene_Article / Article
- 1979. Miller's Anatomy of the Dog. Saunders, Philadelphia. Ed. 2. — OMIA Phene_Article / Article
- 2004. Molecular origins of rapid and continuous morphological evolution. Proc Natl Acad Sci U S A — PubMed:PMID15596718 | DOI:10.1073/pnas.0408118101 — OMIA Phene_Article / Article
- 2024. Ectrodactyly with polydactyly in a dog-Case description and description of surgical therapy with resection and fusion podoplasty. Animals (Basel) — PubMed:PMID38891696 | DOI:10.3390/ani14111647 — OMIA Phene_Article / Article
- 2025. Survey of functional Mendelian variants in New Zealand Huntaway and Heading dog breeds. Anim Genet — PubMed:PMID40965331 | DOI:10.1111/age.70042 — OMIA Phene_Article / Article
Comparative medicine (human OMIM)
Derived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.
- OMIM:174500 (type: trait) — OMIA Group_OMIM (via OMIA_ID)
- OMIM:605522 (type: gene) — OMIA Group_OMIM (via OMIA_ID)
- OMIM:188740 (type: trait) — OMIA Group_OMIM (via OMIA_ID)
verification_derived: method: derived_from_dataset source: "OMIA database dump (omia.xml, local); fields Gene/Variant/Article/OMIM" note: "Structured fields (gene, variant rsID/protein change, PubMed/DOI references, OMIM cross-link) extracted from OMIA dump and presented with first-hand values; not verbatim prose."